Generally, an information input apparatus such as a remote control apparatus is used to input information in order operate a television set, a video recorder, or the like. However, when it comes time to use the remote control apparatus or like, the user may have trouble in locating the apparatus because, for example, the user does not know where the apparatus is placed, and hence the problem that the user cannot use the apparatus when he desires to use it.
In view of the above, there has developed a need for an information input apparatus that is simple to operate and easy to understand and that can be intuitively used by any person without having to operate the information input apparatus itself.
In the prior art, it is known to provide an information input apparatus that projects an image representing an operation unit having a plurality of input keys by using an image projection apparatus, and that detects the motion of a finger on the image by image recognition and determines whether or not an operation has been performed to depress any input key (for example, refer to patent document 1).
In patent document 1, the motion of the finger on the image is detected by first identifying the finger by edge detection from an image read by an imaging unit and then detecting the up-down motion of the finger, that is, the motion of the finger touching the surface on which the image is projected.
It is also known to provide a wearable gesture interface in which a projector is worn by a user and an image of a dial pad is projected on the palm of the user's hand, wherein when the dial pad projected on the palm is pointed to by a device worn on the user's fingertip, an input corresponding to the dial pad thus pointed to is implemented (for example, refer to patent document 2).
In the gesture interface disclosed in patent document 2, the image captured by a camera is analyzed by a computer, and the movement of the device worn on the user's fingertip is tracked to determine whether there is any corresponding input to the dial pad. Further, since the image from the projector is projected after being reflected by a mirror, the user can change the image projection position by manually changing the position of the mirror.
A system is also known in the art which detects a palm within a predetermined range where an image can be projected, and which projects stars, a haiku, or the contents of an illustrated reference book on the detected palm (for example, refer to patent document 3). In the system of patent document 3, the projection direction of the projector is fixed, but since the projection is made over the entire area of the predetermined range, the image is displayed only on the detected palm portion.